Chuck sleeve for bit braces, etc., and method of manufacturing the same



' F. 1. MORAN. CHUCK'SLEVEVE FOR BIT BRACES, ETC.; AND METHOD 0F MANUFACTURING THE SAME.

Y APPLICATION FILED FEB.21,1920.

Patented Apr. 25, 1922.

A ,%N\\\\\\\\\\\\\\\\\\\\\\\ T H 1 T run/f f @ha mi TRANI: a. MORAN, or Naw BRITAIN, CoNNnCTICUT,` AssIsNoR To 'ri-In ivrosn'L Mami- I FACTURING ,corvrrimx or KnNsINeTCN,V

CoNNnCTIcuiT,` a' ConroaaTIoN or CON- CHuCKsLEni/'n ron. BIT simens, ETC., ANDMETHOIJ or MANUFACTURING T "IIE s"A1vIE. l

To ciZZ whom it may concern Be it known that I, :FRANK J. MoniiN,

arcitizen of the United States .of America,V residingat 'New Brita-1n,- Connecticut, have invented a newand'useful Chuck Sleeve for Bit` Braces, Etc., and Methods of Manufacturing theV Same, 'ofwhich the following isl a specification. .Y

My invention-relates to chuck sleeves for bitbra'ces andthe like;y l Y Myinventi'on has for its object. the manufacture ofr such articles from sheet Aor wrought metal inv such a manner that the finished articles are of superior quality.

' lin mynew method of manufacture, andthe finished article itself, constitutes a great ad- -Fu-thermore, the method of manufacture .is such' that :the :same may be very rapidly `produced at a minimum of :expense and witlrpractically no wastage or loss. To the best of my knowledge, Vsuch articles have heretofore'falway's been made from` cast metal, in1fact the very .unusual shape of the Aarticle is such as'to discourage any at-V. tempt to make it ofany other vmaterial.` -IV havehowever solvedthe problem and I am now able to successfully producethem from sheetmetal;V I shall hereinafter show wherel rance in they art.

1 Inthe drawings: l

i Figsfl," and 6 areconventional illustrations-of certain steps in the process of manufacture.

Fig. l shows the finished article, the vcross-` Y i sectional portion showing the interiork coni; tour. It will be'obser'ved that the outer end is contracted so as tov provide'a lcentral opening of yrelatively restricted diameter, while immediatelyvv back ofthis openingis provided whatl will term a tapered j aw contracting wall l. 2-2 represent chuck-jaws of.,4 con- The forward inclined .side wallsof the jaws are engaged by said jaw contracting walll l, so that when the sleeve is ,screwed down, the vjaws will be forced to- .Y ward eachvv other in the `usual manner to counterbored asy indicated at 4.

.manner indicated in Figure 5.

properly gri-p a'toolrbetween'them.` Inas-` much as the rotatable wall l must rubron the non-rotatable jaws 2 2, it follows that speemcauon gf'teurs'ratent, Patented Ap1-' `2'5, 1922, v appiication lfiled February 2i,A laat.A serial 110.3603345.

the surface of this'wallV should *beYV very smooth' and dense to avoid friction and wear,v

Vand to` also permit relatively easyv action inasmuch as ordinarily only the hand is used to .tighten up chucks of this type* Directly back ofthe wallvl',-there is a rela tively large annular cavity `within' the sleeve 1 and vis provided with an'internal thread 3. y

The eXtreme innerl end 'ofthe threadedpor- .y f Y i 5 is a f tion -ofthe bore is Ypreferablyslightly knurling usually provided around thevsleeve tion usually' found on finished chuck sleeves of thistype V j A Y In the preferred manner of Vcarrying'out va' myV invention', I take ai' plate -of wrought or 'sheetyinetal ofthe proper size and thickness, and ,subjectit to a'drawing process ini` .suitable dies, so asto convert it rkinto thev Yform of a cup substantiallyas shown in iFig." Y

of saidcup.. 'Itma-y be necessary to resort to two or morev drawing steps. to reduce the vein which Z represents the die, 8 the mandrell cooperating therewith, and? 9 the side Walls*y y n y cup- VVtol the vdesired final, diametenjwhich .diameter'should-correspondY to the maxim-um .1

diameterof the finished article'. By makin-g Y Y lthe. -die 7 slightly tapered, the outer end of the cupfwall may be made 'somewhat thicker than the inner end, sothatthe wallj of the finis-hed `article at its "outer end willV be thicker than the wall attheinnerf end as is sometimes preferred. The'lower. end of the cup is-then punched out or cut off so as to form j.

anfopenended tube. f VThis tube may be produced in any 4desired manner-but Iprefer inserting a mandrel 1l into the tube in the This mandrel has a smooth tapered jend which correspondsexternally tor the desired shape" andpitch `of theimier .jaw contracting tube is held in such a position that a portion ofthe same projects above the holder l0. Y A die 12 is then applied to the said 'exposed' end kso as to draw in the sides in the manner shown in F ig. 5. The pressure of the die l2 crowds the metal hard against :the tapered end of the mandrel ll and forms at once Ya smoothphard wall of the desired pitch, and of such compactness or density as to wear well and slide freely Yon the'sides ofl the jaws which are to contact therewith.

The next step comprises transferring the sleeve thus partially finished to another holder i3 (see lFig. 6). This holder has a cavity correspondingto the taper of the outer end fof the finished article, and also surrounds thatportiouof the side walls which is to bear the knurling 5. le is a mandrel which `is projected into the center of the tubeV from above, and 15 isa die which is forced down onto the outer side of the eX- posed. end so as to drawV in the side walls against the mandrel lll, and thereby reduce Vthe diameter of Vthat part of the sleeve to make it correspond tothe shape and size of 'the finished article. l H Y The aforesaid few drawing operations result in the production of what l may term be appreciated by a comparison of the old" Y process and articles produced thereby with my new process and the articles produced thereby. ln practicing :the old Yprocess a metal blank is vfirst formed by casting. The external`v dimensionsof vthis cast blank are always substantiallyY greater than the eX- yternal dimensions of the finished chuck sleeve. This cast blank is then subjected to .a machining operation to cut away the outer rough surface of the casting, `and to reduce 'the vexternal dimensions to the desired dimensions of the finished article. This turning down of the outside of the casting is a relatively slow and expensive task involving much labor and wear on tools. to say nothing of breakage and waste of metal. The blank after 'being turned down-must then be placed in a proper grinding machine so as to remove all Vtraces of the tool marks. This likewise requires extra labor and time. The cast metal blank is then smoothed up on the inside by proper tools and a reamer must also Abe introduced to cut away the rough Vsurface of the internal tapered jaw contractand plated.

relance pitch. Tnasmuch as no reamer can be introduced which is of greater diameter than Ythe internal diameter' of the threaded portion, it follows that a relatively -small portion only of this tapered wa'll "can be effectively smoothed up, thereby differing greatly jected to these variousmachining operations the same are inspected and, if found free from imperfections, they are then polished lt is taken for granted that in the manufacture of these articles from cast metal blanks there will be a substantial percentage of waste, due to the imperfections inherent in cast metal, and such wast- `age constitutes a very substantial loss. VTnasniuch as imperfections in the cast metal sleeves are seldom detected until after very much, if not all of the machine work has been completed, it follows that such waste-ge not vonly involves a substantial loss Aof ma-Y eliminated. When they come from the glast die they are. practically finishedrsave for polishing and plating. j y .f f A Comparing the finished articles themselves, my new sleeve is stronger'than alcor- .responding article made from cast metal. lit is also better by reason of the fact that all of the effective parts of the jaw'contracting Wall l is smoothed up Yand the tezture thereof is so compacted that it will be relatively hardV and durable and will lwork rfreely on the jaws. c Y

vnWhat l claim is l. A method of forming :a :seamless wrought iron chuck sleeve for ya bit brace, comprising first forming a seamlesstube, and fthen'subjecting the ends of theV tube to drawingpressure/to reducethe' diameter of both ends thereof, supporting thev tube'on the vinside by ya mandrel, one end of which is tapered, the internal wall ofthe tube adjacent'to the tapered end of the mandrel being forced tightly against said 'tapered end, to smooth and compact the same.

'2jr-X method of forming av seamless comprising first forming a seamless tube, l

then subjecting the ends of the tube to drawing;` pressure to reduce the diameter of "both ends thereof, supporting the tube` on fthe inside by a mandrel, one end of which is jtapered, the internal wall of the tube :adjacent comprising, subjecting a` tube to an endwise and sidewise drawing operationto reduce the two ends thereof in diameter to substantially the diameter of the finished article,

said drawing operations being applied to one end at a time, the interior of said tube being re-inforced by a mandrel having a tapered shaping end durin the first draw ing step to assist in shaplng the forward end of the sleeve, the interior of said tube being re-inforced during the second drawing step by another mandrel of relatively reduced diameter to assist in forming the rear end of said shell.

4. The method of forming a chuck sleeve,

Y comprising; first, drawing up a cup shaped blank from a sheet of metal; next, cutting off the closed end of the cup to form a tube next, drawing in the last mentioned end of the tube to ormi arelatively abrupt contracti ed portion having a smooth internally tapered annular wall; next, drawing in the opposite end of said tube to forma long tubular portion of reduced diameter relatively to the largest diameter of the sleevebut of relatively larger diameter than the opening l through the abruptly contracted'portion.k

Y 5. The method of forming a chuck sleeve, comprising; first, drawing up a cupV shaped blank from a sheetof metal and forming the side wall at the openY end thereoil of greater f Vthickness than the thickness ofv the side wall at the closed end thereof; next, cutting oil' the closed end of the cup to form atube; neXt, drawing inthe last ymentioned endvof the tube to form a relatively abrupt internally tapered annular Wall next, drawing in the oppositeend of said tube t0 form a long tubular portion of reduced diametery relatively to the largest diameter of the sleeve but of relatively larger diameter than the i opening through Y the abruptly Y contracted portion.

FRANK J. MORAN. 

